Methods, arrangements and constructions related to the technical field and structure mentioned above are known in a plurality of different embodiments.
As a first example of the background of technology and the technical field to which the present invention refers may be mentioned an arm structure adapted for a boat transportation carriage, said structure being dimensioned for boats having a displacement of 40 tons, in accordance with the embodiment shown and disclosed in the following, with reference to FIG. 2.
This earlier known boat transportation carriage is adapted as its basic concept to exhibit two elongated frame portions, being parallel to, or at least essentially parallel to, and disposed along the amidships plane or fore- and aft-plane and having said frame portions coordinated with each other, a first and a second frame portion, and with a third frame portion adapted to connect said two frame portions transversely within the frame portion belonging to the front frame portion sections for orientation for forming a “U”-shaped chassis with the two frame portions forming legs of the boat transportation carriage.
Each of said arm structure is adapted to exhibit on the one hand a vertically extending first arm portion and on the other hand a horizontally extending second arm portion, wherein the lower section or portion of the vertically extending arm portion is to be rigidly and solidly connected to a freely movable arm, forming the horizontally extending arm portion, whose arm portion is over a vertically extended axis of rotation rotatable around an axis of rotation.
The lower portion of the vertically extending arm portion is adapted to rest against a chassis, belonging to the boat transportation carriage, and one of its leg-forming frame portions for taking up its allotted portion of the vertical loads, which are based on the deplacement of a boat carried by the boat transportation carriage.
A more specific study of the structure indicated here discloses that the vertical forces, which will operate over the vertically disposed arm portion and the horizontally disposed arm portion, are to be taken up as a torque by one or more used bearing means.
Further it is previously known to having said third frame portion formed as a shaft (having a circular cross section) and that any horizontally torque, between the first and the second frame portions, due to their different vertical movements, are to be transferred to said third frame portion.